Intelligent call redirection

ABSTRACT

An intelligent method is disclosed for handling call redirection to an external service provider (ESP) for subsequent call processing. In one embodiment, a network database ( 30 ) is queried to determine whether the calling party station ( 5 ) has pre-selected an ESP for subsequent call processing. In the event that the calling party station has pre-selected an ESP, the call is automatically redirected to the pre-selected ESP; no caller input is required. If, however, the calling party station has not pre-selected an ESP, an announcement is played to the calling party offering a menu of available ESPs. To accept the offer, the caller must explicitly respond to the offer using, e.g., DTMF signaling. The call is then redirected on a per-call basis in accordance with the calling party&#39;s selection.

This application claims the benefit of U.S. Provisional Application No.60/031,486, filed Dec. 6, 1996.

TECHNICAL FIELD

This invention relates generally to a method for redirecting calls to anexternal services provider (ESP) for subsequent call processing and,more particularly, to an intelligent method for redirecting calls to anESP for the provision of voice messaging.

BACKGROUND

It is known in the art to provide a variety of call services in additionto basic call completion. One such service is automatic voice messagingin which a call encountering a busy or ring-no-answer condition isredirected to a voice messaging platform where the caller can record amessage for the called party. The called party is then provided with amessage waiting indicator (MWI) in the form of a stutter dial tone or aflashing light on the called party's telephone and, the called party,upon detection of the MWI, can dial into the platform to retrieve therecorded message from his/her mailbox.

SUMMARY OF INVENTION

An exemplary method for redirecting a call involving a calling partystation to an external service provider (ESP) for subsequent callprocessing in accordance with the present invention includes: (1)determining whether the calling party station has pre-selected an ESPfor subsequent call processing; (2) if the calling party station haspre-selected an ESP, redirecting the call to the pre-selected ESP; and(3) if the calling party station has not pre-selected an ESP, promptinga calling party at the calling party station to select an ESP and,redirecting the call to the ESP as selected by the calling party.

Other and further aspects of the present invention will become apparentduring the course of the following description and by reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a system architectureimplementing the intelligent call redirection feature of the presentinvention.

DETAILED DESCRIPTION

Referring now to the drawings wherein like reference numerals refer tolike parts, FIG. 1 is a block diagram illustrating a system architectureimplementing the intelligent call redirection feature of the presentinvention. Although not meant to be limiting, the present invention isdescribed in connection with redirection of a call to an externalservice provider for the provision of voice messaging.

A. Network Architecture Elements

1. Signaling System No. 7 (SS7) In the architecture of FIG. 1,end-to-end SS7 connectivity for transmitting out-of-band callingactivity is assumed. For example, SS7 interfaces are provided between:(1) the originating Local Exchange Carrier (LEC) switch 15 and theOriginating Switch 25 (OS); (2) the terminating LEC switch 20 and theTerminating Switch 40 (TS); (3) the OS 25 and the TS 40. The SS7 networkalso supports queries and responses between the OS 25 and the NetworkDatabase 30.

2. Originating Switch (OS)

Upon call initiation, the originating LEC 15 uses the calling party 5number to determine the automatic number identification (ANI) for thecall. The originating LEC 15 then generates an Initial Address Message(IAM) containing the ANI and the calling party number together with anyprivacy indicators and the dialed number (DN) of the called partystation 10, and sends the IAM to the OS 25 over an SS7 data link. In thearchitecture of FIG. 1, the OS 25 is an AT&T 4ESS™ toll switch, thedetails of which are well known in the art.

On each call through the network, the OS 25 queries the Network Database30 using an SS7 Transaction Capabilities (TCAP) Begin Message todetermine both “whether” to offer voice messaging on the call and, “how”to offer it. The TCAP Begin Message contains, among other things: (1)the calling station 5 ANI or calling party number and (2) the dialednumber of the called station 10.

3. Network Database

The Network Database 30 contains customer-specific data regarding thevoice messaging service. This information is used to determine both“whether” to offer voice messaging on the call and “how” to offer it.The Network Database 30 determines whether to invoke voice messagingbased on the caller's service type or the call type (e.g., internationalcalls may not be eligible for voice messaging). The Network Database 30also determines the service preferences and options of the calling andcalled parties (5, 10) from the ANI or calling party number and the DNreceived from the OS and, in so doing, determines “how” to offer voicemessaging on the call.

In accordance with the present invention, there are two modes ofhandling call redirection to an ESP such as a voice messagingprovider—namely, an automatic mode and an on-request mode. ANIs orcalling party numbers which are listed in the Network Database 30 ashaving pre-selected an ESP (e.g., 65 a or 65 b) for voice messaging(i.e., calling party numbers that have a preestablished relationshipwith an ESP) are assigned to the automatic mode. The on-request mode isused for ANIs or calling party numbers which have not pre-selected anESP (65 a,b). In the automatic mode, a Monitoring and Announcement Unit(MAU) 45 (described fully below) monitors call progress signals (e.g.,in-band RNA and out-of-band user or network busy). Calls encountering abusy or RNA are automatically redirected to the pre-selected ESP (65a,b) after the MAU plays an announcement to the calling party 5 (e.g.,“To leave a message, please wait.”). Because the automatic mode does notrequire any caller interaction, it provides rotary dial customers accessto an ESP and thus, to call services such as voice messaging. In theon-request mode, upon busy or RNA, the MAU 45 will play an announcementto the calling party offering a menu of available ESPs (65 a,b) (e.g.,“To leave a message press 1 for AT&T Messaging, press 2 for ABCmessaging, press 3 for XYZ messaging.”). The MAU 45 will then monitorfor a response from a caller at the calling party station 5. The callercan select an ESP (on a per-call basis) by pressing the digit on thetouch-tone keypad of his telephone or, alternatively, speaking a digitcorresponding to the desired ESP (65 a,b). Entry of an ESP selectiondigit will initiate call redirection to the desired ESP.

Additional service preferences and options include: (1) disable voicemessaging (as specified by the calling or called party 5, 10) and (2)customized rings (the number of rings that defines a RNA condition andis the larger of the value specified by the ANI or the DN, or otherwisea default value). With respect to the disable option, a DN correspondingto a called party station 10 which is not conducive to voice messagingcould thus disable voice messaging on all calls made to that number.Examples of such DNs include those associated with payphones, facsimilemachines and computer dial-in numbers.

If the Network Database 30 decides to invoke voice messaging on thecall, it forwards instructions to the OS 25 (via a TCAP InstructionMessage) to route the call through the MAU 45. The Network Database 30also forwards to the OS 25 via the same Instruction Message: (1) aRedirection Feature ID (i.e., automatic mode or on-request mode); (2) atimer value that corresponds to the number of rings that defines a RNAcondition; (3) an ESP identifier (for automatic mode the caller'spre-selected ESP identifier is returned; for the on-request mode, a“best-guess” {e.g., entirely random} ESP identifier is returned); (4) aRedirection Number (RN) which is used to redirect the call to the ESP;and (5) an indication of which ESPs support voice messaging for callsoriginating from the NPA-NXX of the caller's ANI.

The OS 25 then sends the information contained in the TCAP instructionmessage to the MAU 45, routes the call through the MAU 45 and sets upthe call to the TS 40 associated with the DN.

4. Monitoring and Announcement Unit (MAU)

When the MAU 45 is invoked on a call, the call path is “hair-pinned”through the MAU 45. As indicated above, the MAU 45 monitors for variousin-band triggers such as call progress signals (e.g., user busy or RNA)and entry of DTMF or voice signals by the caller (e.g., entry by thecaller of an ESP selection digit from the touch-tone keypad of thecalling station 5 or, alternatively, entry by the caller of an ESPselection digit by speaking the digit into the transceiver of thecalling station 5). The MAU 45 also uses out-of-band message processingfor the detection of out-of-band triggers such as call progress signals(e.g., network busy). In response to trigger detection, the MAU 45 playsvarious announcements (e.g., service offerings) to the caller at thecalling station 5.

When a call is hair-pinned through the MAU 45, the OS 25 actually “sees”two separate calls: (1) an “incoming” call from the calling party 5 tothe MAU 45 and (2) an “outgoing” call from the MAU 45 to the calledparty 10. The “incoming call” is referred to as the “P1” leg, and the“outgoing call” is referred to as the “P2” leg.

Although the OS 25 “sees” two separate calls, the MAU 45 knows that theP1 and P2 legs are tied together. The MAU 45 software has both a “Merge”capability and “Redirect Call” capability. A “Merge” is used to tietogether a P1 and P2 leg when both legs are already established. Forexample, a merge is used to tie together (1) a first call between acalling party 5 and the OS 25 and (2) a second call between the OS 25and the called party 10, as soon as the called party 10 answers thecall. A “Redirect Call” is used to tie together a P1 leg with a P2 legwhich has yet to be established. For example, when a call beingmonitored by the MAU 45 is to be redirected to an ESP (65 a,b), aRedirect Call is performed. In such instances, the following steps areexecuted: (1) the outgoing trunk (P2) is removed; (2) the MAU 45instructs the OS 25 to redirect the call to the ESP (65 a,b); and (3)the MAU 45 is disabled (i.e., the MAU 45 is no longer included in thecall).

5. Terminating Switch (TS) for the ESP

If the call is redirected to an ESP (65 a,b), the TS (55 a,b) for theESP uses Call Redirection Service over a Primary Rate Interface 70 (PRI)to terminate the call at the ESP. After the calling party records amessage and goes on-hook, the network tears down the call path.

To initiate call set-up between the OS 25 and the selected ESP (65 a,b),the OS 25 first sends an ISUP IAM message to the TS (55 a,b) servicingthe ESP (65 a,b). The TS (55 a,b) then converts the IAM message into aSet-Up message for transmission to the ESP (65 a,b). Signaling betweenthe TS (55 a,b) and the ESP (65 a,b) is via an ISDN D channel. TheSet-Up message includes the following information: the ANI, the RN andthe DN together with the “reason for redirection” (e.g., no answer orbusy). The reason for redirection can be used by the ESP (65 a,b) tovary the timing of message delivery (e.g., if the reason for redirectionwas busy, the ESP (65 a,b) would want to commence forced delivery soonerthan if the reason for redirection was no answer).

The ESP (65 a,b) then sends (1) a Call Proceeding message to the TS (55a,b) which maps the message into a Progress message that is sent to theOS 25 and (2) a Connect message to the TS (55 a,b) which is mapped intoan Answer message sent to the OS 25. The TS (55 a,b), in turn, sends aConnect Acknowledge message to the ESP (65 a,b) which is then preparedto receive the call. Upon receiving an Answer message, the OS 25cuts-through the call to the TS (55 a,b), and hence, to the ESP (65a,b), where the caller 5 can record a message for the originally calledparty 10 number.

B. Exemplary Call Flows

Three call flow scenarios are presented below: (1) automatic mode voicemessaging (pre-selected ESP); (2) on-request mode voice messaging—onlyone ESP; and (3) on-request mode voice messaging—multiple ESPs.

1. Automatic Mode Voice Messaging (pre-selected ESP)

a. The OS 25 receives a call from the LEC 15.

b. The OS 25 queries the Network Database 30 (the query message includesthe caller's ANI and the DN). The Network Database 30 containsinformation about the calling party station and the called party station(5, 10), and retrieves this information using the received ANI and DN,respectively.

c. The Network Database 30 determines, based on the caller's servicetype and the call type, whether to invoke MAU 45 to assist inredirection to an ESP for subsequent call processing such as voicemessaging. If the foregoing indicates that the MAU 45 is to be invokedon the call, the Network Database 30 also determines the preferences andoptions for the calling and called parties. The following preferencesand options are available: (1) Automatic Mode Voice Messaging (ESPpre-selected by calling party); (2) On-Request Mode Voice Messaging (ESPnot pre-selected by calling party); (3) Disable Voice Messaging (asspecified by the calling or called party); and (4) Customized rings (thenumber of rings defining a RNA condition as also specified by thecalling or called party).

d. If the MAU 45 is to be invoked on the call, the Network Database 30returns a response to the OS 25 which includes: (1) an invoke MAU 45parameter; (2) the Redirection Feature ID (either automatic oron-request mode voice messaging; as described below, the on-request modeFeature ID may also depend upon whether a single or multiple ESPs areavailable); (3) the RNA Timer value; (4) the ESP ID (in the NetworkDatabase 30, an ESP ID is associated with every ANI that haspre-selected an ESP. For those ANIs that have not pre-selected an ESPand have not disabled call redirection for voice messaging, the NetworkDatabase 30 will return the only available ESP ID in the event that asingle ESP is available and a “best-guess” ESP ID in the event thatmultiple ESPs are available); (5) the Redirection Number (RN) (theNetwork Database 30 will determine the routing to the ESP based ontranslations of the NPA-NXX of the dialed number 10); and (6) anindication of which ESPs support voice messaging for calls originatingfrom the NPA-NXX of the dialed number 10.

e. OS 25 routes the call through the MAU 45 to the TS 40 and passes theinformation obtained from the Network Database 30 to the MAU 45. The MAU45 saves the following information obtained from the Network Database 30as per call data: ESP ID, RN, RNA timer value, and indicator of ESPsupport. In addition, the MAU stores the ANI and Calling Party Number(CPN) with privacy indicators, and the DN.

f. If the MAU 45 detects that the call is answered, the MAU 45 instructsthe OS 25 to merge the two legs of the call and disable the MAU 45.

g. If the MAU 45 detects in-band ringing, the MAU 45 starts a RNA timer.If the MAU 45 detects in-band/out-of-band user busy, or out-of-bandnetwork busy, or the RNA timer expires and the Feature ID indicates“Automatic Mode”, then the MAU 45 plays the Automatic Mode Point of SaleAnnouncement (POSA). For example: “To leave a message, please wait.”Thus, an automatic mode customer need not enter any digits to effectcall redirection.

h. If the caller 5 remains on the call after the Automatic Mode POSA iscomplete, the MAU 45 performs the following steps to redirect the call:(1) passes the RN along with the ANI and CPN with presentationindicators to the OS 25; (2) instructs the OS 25 to redirect the call tothe ESP platform (65 a,b) using the RN; and (3) instructs the OS toremove the MAU 45 from the call and merge the two legs of the call. Inthe automatic mode, a built-in delay period between the end of the POSAand the start of rerouting is used to provide the caller 5 with areasonable period of time in which to decline voice messaging (i.e., tohang up). This delay period also avoids the expense incurred by thenetwork of redirecting the call unnecessarily.

i. The OS 25 redirects the call to the appropriate ESP platform (65 a,b)using the RN and passes along the ANI and CPN together with associatedprivacy indicators and the DN.

j. When the TS (55 a,b) serving the ESP platform (65 a,b) receives thecall, the TS (55 a,b) sends the ESP platform (65 a,b) an ISDN Q.931SETUP Message which includes the following information elements:

(1) Calling Party Number (CPN)=caller's (5) ANI or CPN with privacyindicator

(2) Called Party Number (CdPN)=Redirection Number (RN) of ESP

(3) Redirecting Number=Originally Dialed Number (DN) and reason forredirection (e.g., no answer, user busy, network busy).

k. If the caller (5) stays on the line, the ESP platform (65 a,b)answers the call.

l. Once the call is answered by the ESP platform (65 a,b) (i.e., the ESPplatform returns Answer Supervision), the call flow in the Network isidentical to a POTS call.

m. The ESP (65 a,b) uses the Redirecting Number (the original DN) as theaddress of the called party's mailbox and, plays a greeting to thecaller.

n. After the greeting, the caller leaves a message.

o. The platform (65 a,b) notifies the called party 10 that a message isin the called party's mailbox by a message waiting indicator (e.g., alamp on the called party's phone) or via a phone call to the messagerecipient.

2. On-Request Mode Voice Messaging—Only One ESP

Steps a-f are the same as for Automatic Mode Voice Messaging.

g. If the MAU 45 detects in-band ringing, the MAU 45 starts the RNAtimer and begins monitoring for caller 5 entered DTMF or spoken digitscorresponding to an ESP (65 a,b). Digit collection is also enabled forin-band/out-of-band busy. An ESP selection digit can be entered by thecaller any time after ringing or busy has been detected by the MAU 45and before answer to immediately redirect the call to the ESP (65 a,b)rather than waiting for expiration of the RNA timer or completion of thePOSA (see Step g.′, below).

g.′ If the MAU 45 detects in-band/out-of-band busy or the RNA timerexpires and the Feature ID indicates “On-Request Mode VoiceMessaging—only one ESP”, the MAU 45 plays the On-Request Mode—Only OneESP POSA. The POSA may be, for example, “To leave a message, press orsay 1 for AT&T Messaging.”

h. If the caller 5 presses or speaks an ESP selection digit, the MAU 45checks the indicator of ESP support to see if the digit is a valid ESPselection digit. If the caller presses a valid ESP selection digit, theMAU 45 then performs the following steps to redirect the call: (1)passes the RN together with the ANI and CPN with presentation indicatorsto the OS 25; (2) instructs the OS 25 to redirect the call to the ESPplatform (65 a,b) using the RN; (3) instructs the OS 25 to remove theMAU 45 from the call and merge the two legs of the call.

The remaining steps are the same as for Automatic Mode Voice Messaging.

3. On-Request Mode Voice Messaging—Multiple ESPs

Steps a-f are the same as for Automatic Mode Voice Messaging.

g. Same as for On-Request Mode Voice Messaging—Only One ESP

g.′ If the MAU 45 detects in-band/out-of-band busy or the RNA timer hasexpired and the Feature ID indicates “On-Request Mode VoiceMessaging—Multiple ESPs”, the MAU 45 plays the On-Request Mode MultipleESP POSA.

The POSA may be, for example, “To leave a message, press or say 1 forAT&T Messaging, press or say 2 for ABC messaging, press or say 3 for XYZmessaging.”

h. If the caller presses or speaks a valid ESP selection digit, asdetermined by the indicator of ESP support, then one of two scenariosresult:

(1) if the ESP selection digit corresponds to the ESP ID stored in theMAU 45, then the MAU 45 performs the following steps: (a) passes the RNtogether with the ANI and CPN with presentation indicators to the OS;(b) instructs the OS to redirect the call to the ESP platform using theRN; and (c) instructs the OS to remove the MAU 45 from the call andmerge the two legs of the call, or

(2) if the ESP selection digit does not correspond to the ESP ID storedin the MAU 45, then the MAU 45 performs the following steps: (a) passesthe ANI and CPN with presentation indicators to the OS; (b) instructsthe OS to query the Network Database 30 to obtain the RN of the ESPselected and redirect the call; and (c) instructs the OS to remove theMAU 45 from the call and merge the two legs of the call.

The remaining steps are the same as for Automatic Mode Voice Messaging.

The many features and advantages of the present invention are apparentfrom the detailed specification, and thus, it is intended by theappended claims to cover all such features and advantages of theinvention which fall within the true spirit and scope of the presentinvention.

Furthermore, since numerous modifications and variations will readilyoccur to those skilled in the art, it is not desired that the presentinvention be limited to the exact construction and operation illustratedand described herein, and accordingly, all suitable modifications andequivalents which may be resorted to are intended to fall within thescope of the claims.

We claim:
 1. A method for handling redirection of a call involving acalling party station to an external service provider (ESP) forsubsequent call processing, comprising the steps of: determining whetherthe calling party station has pre-selected an ESP for the subsequentcall processing; if the calling party station has pre-selected an ESP,redirecting the call to the pre-selected ESP; if the calling partystation has not pre-selected an ESP, prompting a caller at the callingparty station to select an ESP and, redirecting the call to the selectedESP, wherein the determining step occurs before detection of aredirection trigger and the prompting step occurs after detection of theredirection trigger.
 2. The method of claim 1 wherein the determiningstep includes the step of transmitting call origination information to adatabase containing customer specific data regarding the subsequent callprocessing.
 3. The method of claim 1 wherein the step of redirecting thecall to the pre-selected ESP is in direct response to the redirectiontrigger.
 4. The method of claim 1 wherein the step of redirecting thecall to the selected ESP is in direct response to entry of an ESPselection digit by a caller at the calling party station.
 5. The methodof claim 1 wherein the subsequent call processing is voice messaging andthe redirection trigger is a busy or ring-no-answer condition.
 6. Themethod of claim 1 further comprising the step of determining whethereither the calling party station or the called party station hasspecified a number of unanswered rings that constitutes a ring-no-answercondition for voice messaging.
 7. The method of claim 6 wherein thedetermining steps include the step of transmitting call originationinformation and call destination information to a database containingcustomer specific data regarding voice messaging.
 8. A method forhandling redirection of a call involving a calling party station to anexternal service provider (ESP) for subsequent call processing,comprising the steps of: determining whether the calling party stationhas pre-selected an ESP for the subsequent call processing; determiningwhether the calling party station has disabled the subsequent callprocessing on calls made from the calling party station; determiningwhether the called party station has disabled the subsequent callprocessing on calls made to the called party station; when the callingparty station has pre-selected an ESP, redirecting the call to thepre-selected ESP; when the calling party station has not pre-selected anESP, prompting a caller at the calling party station to select an ESPand, redirecting the call to the selected ESP; and when either thecalling party station or the called party station has disabled thesubsequent call processing, not performing the prompting step and theredirecting steps on the call.
 9. The method of claim 8 wherein thedetermining steps include the step of transmitting call originationinformation and call destination information to a database containingcustomer specific data regarding the subsequent call processing.
 10. Themethod of claim 8 wherein the determining steps occur before detectionof a redirection trigger and the prompting step occurs after detectionof the redirection trigger.
 11. The method of claim 8 wherein the stepof redirecting the call to the pre-selected ESP is in direct response toa call progress redirection trigger.
 12. The method of claim 8 whereinthe step of redirecting the call to the selected ESP is in directresponse to entry of an ESP selection digit by a caller at the callingparty station.
 13. The method of claim 10 wherein the subsequent callprocessing is voice messaging and the redirection trigger is a busy orring-no-answer condition.
 14. The method of claim 13 further comprisingthe step of determining whether either the calling party station or thecalled party station has specified a number of unanswered rings thatconstitutes a ring-no-answer condition for voice messaging.
 15. Themethod of claim 14 wherein the determining steps include the step oftransmitting call origination information and call destinationinformation to a database containing customer specific data regardingvoice messaging.
 16. A method for handling redirection of a callinvolving a calling party station and a called party station to a voicemessaging provider, comprising the steps of: transmitting callorigination information to a database to determine whether the callingparty station has pre-selected a voice messaging provider; receiving aresponse from the database indicating whether the calling party stationhas pre-selected a voice messaging provider; detecting a busy orring-no-answer condition on the call; when the calling party station haspre-selected a voice messaging provider, automatically redirecting thecall on busy or ring-no-answer to the voice messaging provider; when thecalling party station has not pre-selected a voice messaging provider,prompting a caller at the calling party station on busy orring-no-answer to select a voice messaging provider for the call;monitoring the call for the caller's selection of a voice messagingprovider; redirecting the call in accordance with the caller's selectionof a voice messaging provider.
 17. A method for handling redirection ofa call involving a calling party station to an external service provider(ESP) for subsequent call processing, comprising the steps of:determining whether the calling party station has pre-selected an ESPfor the subsequent call processing; detecting a call progressredirection trigger; and upon detection of the call progress redirectiontrigger: if the calling party station has pre-selected an ESP,redirecting the call to the pre-selected ESP; if the calling partystation has not pre-selected an ESP, prompting a caller at the callingparty station to select an ESP and, redirecting the call to the selectedESP.
 18. The method of claim 17 wherein the determining step occursbefore detection of the call progress redirection trigger.
 19. Themethod of claim 17 wherein the step of redirecting the call to thepre-selected ESP is in direct response to the call progress redirectiontrigger.
 20. The method of claim 17 wherein the step of redirecting thecall to the selected ESP is in direct response to entry of an ESPselection digit by a caller at the calling party station.
 21. The methodof claim 17 wherein the subsequent call processing is voice messagingand the call progress redirection trigger is a busy or ring-no-answercondition.